Overview

• Hubble observations on July 21 constrain 3I/ATLAS’s nucleus and capture a dust plume with a hint of a tail, confirming comet-like outgassing.
• The comet is streaking through the Solar System at about 210 000 km/h, making it the fastest visitor yet recorded and reflecting billions of years in interstellar drift.
• Planned James Webb Space Telescope spectroscopy and continued ground- and space-based monitoring aim to refine its chemical composition before September.
• NASA is assessing a Juno spacecraft retargeting for a potential early-2026 flyby, and ESA’s Comet Interceptor, set to launch in 2029, is poised to study future interstellar targets.
• Despite mounting evidence for a natural origin, Harvard astronomer Avi Loeb’s proposal of an artificial origin remains under discussion pending additional data.